Help needed with transistor substitution

Many on that list are also obsolete.
About the only TO-92 device available from ON Semi is the BF256B. Intended for RF, but same process line as many of their JFETs including low noise devices.
On Semi list a few SMD devices e.g.SMD equivalents to 2N5484-5-6 (MMBF5484 etc), BSR57 and 2SK3666 for example may be suitable.
I'm using BF256B's in an amp without a problem.